Almost Like Our Saturn, But 5000 Light Years Away

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Almost Like Our Saturn, But 5000 Light Years Away

In an unexpected stroke of luck, astronomers have found two planets that resemble smaller versions of Jupiter and Saturn (that's our Saturn in the picture to the right) in a solar system nearly 5000 light years away from Earth.

While the discovery of so-called exoplanets is becoming more common (though if you ask me, never less exciting), this particular technique helps support the idea that solar systems like ours are in fact very common in our galaxy.

The scientists were studying a phenomenon called gravitational microlensing, in which the gravity of one star bends and focuses the light from a more distant star, strengthening it as though it were passing through a glass lens. In this case, the star being observed magnified the light from a distant star by more than 500 times, researchers said.

But while watching this process, from March to early April of 2006, they saw a small distortion in the light, seeming to indicate a Saturn-sized planet.

More surprisingly, a second such "blip" came less than a day later, with data that suggested the presence of a second, larger planet.Subsequent analysis of the data has borne out those conclusions.

"This is the first time we had a high-enough magnification event where we had significant sensitivity to a second planet – and we found one,"(Ohio State University astronomer Scott) Gaudi said. "You could call it luck, but I think it might just mean that these systems are common throughout our galaxy."

The solar system's star is dimmer than ours, and the two exoplanets, apparently giant gas planets like Saturn and Jupiter, smaller than their local counterparts. But the ratio between their masses and the mass of the sun is similar to that of Saturn and Jupiter and our own sun. Says Gaudi:

"Theorists have wondered whether gas giants in other solar systems would form in the same way as ours did. This system seems to answer in the affirmative."

A paper on the discovery is being published in the Feb. 15 issue of Science.